private void InitializeClient()
        {
            UserSignIn signin = new UserSignIn(this._LyncClient);

            signin.StartUpLync(false);

            //***********************************************************************************
            // This application works with UISuppressionMode = true or false
            //
            // UISuppressionMode hides the Lync user interface.
            //
            // Registry key for enabling UISuppressionMode:
            //
            // 32bit OS:
            // [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\15.0\Lync]
            // "UISuppressionMode"=dword:00000001
            //
            // 64bit OS:
            // [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Communicator]
            // "UISuppressionMode"=dword:00000001
            //
            // When running with UISuppressionMode = 1 and this application is the only one
            // using the client, it's necessary to Initialize the client. The following check
            // verifies if the client has already been initialized. If it hasn't, the code will
            // call BeginInitialize() proving a callback method, on which this application's
            // main UI will be presented (either Sign-In or contact input, if already signed in).
            //***********************************************************************************

            //if this client is in UISuppressionMode...
            if (_LyncClient.InSuppressedMode && _LyncClient.State == ClientState.Uninitialized)
            {
                //...need to initialize it
                try
                {
                    _LyncClient.BeginInitialize(this.ClientInitialized, null);
                }
                catch (LyncClientException lyncClientException)
                {
                    Console.WriteLine(lyncClientException);
                }
                catch (SystemException systemException)
                {
                    if (Utilities.IsLyncException(systemException))
                    {
                        // Log the exception thrown by the Lync Model API.
                        Console.WriteLine("Error: " + systemException);
                    }
                    else
                    {
                        // Rethrow the SystemException which did not come from the Lync Model API.
                        throw;
                    }
                }
            }
            else //not in UI Suppression, so the client was already initialized
            {
                //registers for conversation related events
                //these events will occur when new conversations are created (incoming/outgoing) and removed
                _LyncClient.ConversationManager.ConversationAdded   += ConversationManager_ConversationAdded;
                _LyncClient.ConversationManager.ConversationRemoved += ConversationManager_ConversationRemoved;

                //show sign-in or contact selection
                //ShowMainContent();
            }
        }
        private void InitializeClient()
        {
            UserSignIn signin = new UserSignIn(this._LyncClient);
            signin.StartUpLync(false);

            //***********************************************************************************
            // This application works with UISuppressionMode = true or false
            //
            // UISuppressionMode hides the Lync user interface.
            //
            // Registry key for enabling UISuppressionMode:
            //
            // 32bit OS:
            // [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\15.0\Lync]
            // "UISuppressionMode"=dword:00000001
            //
            // 64bit OS:
            // [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Communicator]
            // "UISuppressionMode"=dword:00000001
            //
            // When running with UISuppressionMode = 1 and this application is the only one
            // using the client, it's necessary to Initialize the client. The following check
            // verifies if the client has already been initialized. If it hasn't, the code will
            // call BeginInitialize() proving a callback method, on which this application's
            // main UI will be presented (either Sign-In or contact input, if already signed in).
            //***********************************************************************************

            //if this client is in UISuppressionMode...
            if (_LyncClient.InSuppressedMode && _LyncClient.State == ClientState.Uninitialized)
            {
                //...need to initialize it
                try
                {
                    _LyncClient.BeginInitialize(this.ClientInitialized, null);
                }
                catch (LyncClientException lyncClientException)
                {
                    Console.WriteLine(lyncClientException);
                }
                catch (SystemException systemException)
                {
                    if (Utilities.IsLyncException(systemException))
                    {
                        // Log the exception thrown by the Lync Model API.
                        Console.WriteLine("Error: " + systemException);
                    }
                    else
                    {
                        // Rethrow the SystemException which did not come from the Lync Model API.
                        throw;
                    }
                }
            }
            else //not in UI Suppression, so the client was already initialized
            {
                //registers for conversation related events
                //these events will occur when new conversations are created (incoming/outgoing) and removed
                _LyncClient.ConversationManager.ConversationAdded += ConversationManager_ConversationAdded;
                _LyncClient.ConversationManager.ConversationRemoved += ConversationManager_ConversationRemoved;

                //show sign-in or contact selection
                //ShowMainContent();
            }
        }